Hi Greg, On 11/21/19, Greg KH <greg@xxxxxxxxx> wrote: > On Thu, Nov 21, 2019 at 05:06:45PM +1100, JH wrote: >> Hi Peter, >> >> On 11/21/19, Peter Chen <peter.chen@xxxxxxx> wrote: >> > On 19-11-21 07:08:32, JH wrote: >> >> Hi Greg, >> >> >> >> On 11/21/19, Greg KH <greg@xxxxxxxxx> wrote: >> >> > On Wed, Nov 20, 2019 at 09:28:14PM +1100, JH wrote: >> >> >> Hi, >> >> >> >> >> >> I am running 4G LTE (USB protocol) and WiFi on IMX6 board, the >> >> >> kernel >> >> >> is 4.19.75 LTE. It is not clear where the kernel alignment trap >> >> >> came >> >> >> from, the only thing I could see is the alignment trap message >> >> >> generated immediate after USB GSM communication or mwifiex_sdio. >> >> >> Where >> >> >> that the alignment trap came from? Which parts of the program could >> >> >> contribute the kernel alignment trap, kernel iteself, or USB GSM or >> >> >> mwifiex_sdio? Appreciate clues how to fix it. >> >> >> >> >> >> Nov 20 05:08:09 solar kernel: usb 1-1: GSM modem (1-port) converter >> >> >> now attached to ttyUSB0 >> >> >> Nov 20 05:08:09 solar kernel: option 1-1:1.2: GSM modem (1-port) >> >> >> converter detected >> >> >> Nov 20 05:08:09 solar kernel: usb 1-1: GSM modem (1-port) converter >> >> >> now attached to ttyUSB1 >> >> >> Nov 20 05:08:10 solar kernel: mwifiex_sdio mmc0:0001:1: info: >> >> >> trying >> >> >> to associate to 'Solar Analytics Wifi' bssid 78:8a:20:49:4b:c5 >> >> >> Nov 20 05:08:10 solar kernel: mwifiex_sdio mmc0:0001:1: info: >> >> >> associated to bssid 78:8a:20:49:4b:c5 successfully >> >> >> Nov 20 05:08:10 solar kernel: IPv6: ADDRCONF(NETDEV_CHANGE): mlan0: >> >> >> link becomes ready >> >> >> Nov 20 05:23:13 solar kernel: mwifiex_sdio mmc0:0001:1: info: >> >> >> successfully disconnected from 78:8a:20:49:4b:c5: reason code 3 >> >> >> Nov 20 05:23:13 solar kernel: IPv6: ADDRCONF(NETDEV_UP): mlan0: >> >> >> link >> >> >> is not ready >> >> >> Nov 20 05:23:18 solar kernel: Alignment trap: not handling >> >> >> instruction >> >> >> e8532f00 at [<b6c802b6>] >> >> >> Nov 20 05:23:18 solar kernel: Unhandled fault: alignment exception >> >> >> (0x001) at 0x38626667 >> >> >> Nov 20 05:23:18 solar kernel: pgd = 34bdb7e7 >> >> >> Nov 20 05:23:18 solar kernel: [38626667] *pgd=00000000 >> >> > >> >> > You should have a much longer tracedump after this, right? Can you >> >> > provide that please? >> >> >> >> That was the last statement from the kernel log journalctl -t kernel >> >> -b at the time. >> >> >> >> > And why do you think this was a USB issue? >> >> >> >> No, I was not saying it was a USB issue, nor did I know if it is a >> >> kernel issue or mwifiex_sdio issue or something else, I don't have the >> >> knowledge to determine it, that was why I have to go this list for >> >> help, I did try to connect to Linux network mailing list linux-net or >> >> kernel mailing list lkml, but I must get wrong with the mailing list >> >> address, I could not get response or subscription frin linux-net or >> >> lkml, if you could let me know the correct kernel network mailing >> >> address and kernel mailing list address, I'll ask the help there as >> >> well. >> >> >> > >> > Do you have correct firmware has loaded for your device? >> >> Not clear what the firmware you were talking about? I used open source >> linux-firmware-sd8887, uBlox SARA-R4 and uBlox EMMY on IMX6. Let's say >> we have been running this device for about 7 months, we used Kernel >> 5.1.0 before, I could not recall any error about the alignment trap in >> kernel. We now moved to kernel 4.19.75 LTS, that is what it occurred >> often, that worries me. > > Why did you move to an older kernel? If it all works on a newer one, > please stick with that, or use 'git bisect' to find the commit that > breaks things. My CTO wanted LTS and could not wait for 5.4, I did forward your blog Linux Kernel Release Model for my CTO to read it, if it is caused by kernel 4.19, I'll talk to the CTO again. Thank you. - jh
